There aren't a lot of secrets to these cars. What you see, is pretty much what you get. If the car looks and runs well and has a consistant service history, you are good to go.

Then there is price....

I am going to look at a '91 70,000mi. M5 today. The seller claims it to be very tight, and leak free, but even with this in mind, what should I be looking for? I am used to driving an e36, which is a point and shoot car compared to the e34 m's.